Pulverized-fuel burner.



L. H. BERGIVIAN.

PULVERIZED FUEL BURNER.

APPLICATION FILED IuLY I6. I9I5.

Patented Jan. 30, 1917.

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L. H. BERGMAN.

PULVERIZED FUEL BURNER.

APPLICATION FILED IULY I6. I9I5.

ILM Sm, Patend Jan. 30, 1917.

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any IV. ew man CII LABS EI. BERGMAN, 0F PHILADELPHIA, PENNSYLVNIA.

PULVERZED-JEUEL BURNER.

terasse.

Specification of Letters Patent.

Application tiled July 16, 1015. Serial No. 450,172.

Be it known that f, Lans H. BERGMAN, a subject of the King of Sweden, residing at Philadelphia, county of Philadelphia, 'and State of Pennsylvania, have invented a new and useful Improvement in Pulverized-Fuel Burners, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this specification. v

'llhe invention relates to pulverized fuel burners for furnaces, boilers and kilns wherein air is employed both to atomize and propel thel fuel and to effect combustion.

'lhe main object of the invention is to so construct the burner as to require only one source of air supply. rlhis object is effected by a construction in which the common 'supply of air is so divided that the part thereof used for combustion is supplied either on the outside or on the inside of the stream of air employed for atomizing and carrying the fuel. p

ln this patent there is set forth and specically claimed an embodiment of the inventionfv-wherein the combustion air takes a path surrounding the passage for the fuel and atomizing vand carrying air and there isy also claimed the subject-matter common to the two arrangements mentioned; while in applications filed of even date herewith, Serial Nos. 40,173 and 40,174, there are set forth and specifically claimed embodiments of the invention wherein the combustion air passes inside the surrounding stream of fuel andatomizing and carrying air.

ln the drawings, which show a preferred embodiment of one type of the invention: Figure 1 is a sectional elevation.v lFig. 2 is a horizontal sectional view ofthe burner. Fig. 8 is a front view of the burner. Fig. 4 is a sectional elevation of a modification. lFigs. 5 and 6 are horizontal sectional views of the nozzle in diHerent adjusted positions.

'llhe inlet opening b for the pulverized fuel is connected to a pipe a through which the fuel is fed, in proper and uniformamount, by any known means, the fuel dropping by gravity through the opening b and a cone c into the inner pipe d of the burner. Pipe d is so shaped as to oder the minimum resistance to the flow of the pulverized fuel. lfts inlet end is so shaped that with cone c in place it causes the air, beyond the inlet mouth of the pipe, to increase somewhat in pressure, also giving the air such a direction as to create a slight suction in cone c. Surrounding the fuel pipe al, except at the discharge end of the latter, is a casting or pipe e for the passage of the combustion air. Uuter pipe e extends above cone c, and carries or contains inlet opening b above menlFatented an.. 30, it?.

tioned. At one side of itsupper end, pipe e y is provided with an air inlet nected with a supply of air. v

lnner pipe d may be positioned within outer pipe e by any suitable means, as, for instance, by a foot support g and set screws it'. At its upper end, opposite the air inlet f, pipe@ issomewhat enlarged to form an air chamber i having a capacity larger than the volume of air discharged at the burner nozzle, thereby always forcing the desired proportion of atomizing air and combustion air through the burner. It will be understood that the relation between inlet fand air chamber 'need not be as shown and described, nor is it necessary to connect the inlet to the burner at any particular angle or at any particular point. Nor are the number of air inlets of importance. These details, as well as other details herein set forth, may vary with the individual installations and with the preferences of designers.

At the end of outer pipe e is a nozzle la which has a converging discharge mouth and is movable longitudinally of pipe e to vary the area of the passage for the combustion air. By so adjusting the nozzle, the length and shape of the flame may be varied and at ithe same time the amount of combustion air increased or decreased. rll`hereby, within the capacity of the burner, the amount of combustion air may be regulated to corref, which is conspond to the variation in fuel consumption,"

.pipe d and nozzle lf: are broadened in one dimension land flattened lin a dimension at right angles thereto. v'its the pipe d changes its cross-sectional shape it is slightly increased in area, thereby reducing'the renozzle o and the outlet ends of the cast-ingVV p and inner tube 1' are circular in cross-section. This construction is one whereby a comparatively long, cylindrical-shaped flame is obtained, the combustion taking place at some distance from the burner. The nozzle has a conical discharge end and is adjustable, as shown in Figs. 5 and 6, to vary the amount of combustion air and to regulate the length of the flame. For this purpose, the nozzle may have a direct sliding movement similary to that given nozzle k, or it may have a threaded engagement with the casting, as shown.-

In the operation of the burner it will be understood that the pulverized fuel drops by gravity into the inner pipe al of the burner and that the atomizing yair entering the pipe around the cone c breaks up the solid flow of pulverized fuel and assists in carrying it through the inner pipe and blows it in suspension into ,the furnace boiler or kiln; and that the combustion air enters the surrounding passage of larger area and mixes with the fuel and the fuel atomizing and propelling air at and beyond the mouth of the'nozzle.

Having now fully described my invention,

what I claim and desire to protect by Letters-Patent is:

l. A pulverized fuel burner comprising an outer pipe and an innei` pipe whose dis charge ends extend horizontally, an inlet for air under pressure common to both pipes and communicating therewith at their rear ends,

a downwardly extending fuel supply chamber provided with an outlet arranged to receive the coal by gravity, said fuel outlet communicating directly with one of said pipes and opening forwardly thereinto in the direction of the flow of air therethrough, whereby the propulsion and combustion of the fuel isl effected with the use of but one source of air supply.

2. A pulverized fuel burner comprising an outer air pipe and an inner air and fuel pipe, said pipes being -eurved to provide horizontally extending discharge ends and vertically extending admission ends, a chamber for air under pressure common to both pipes arranged above the admission ends of the pipes, and a fuel inlet extending downwardly into the admission end of the inner pipe.

3. A pulverized fuel burner comprising an inner fuel carrying pipe, an outer combustion air pipe, a fuel inlet to the inner pipe, and means to supplyY air to both pipes, the inner pipe having longitudinal c'orrugations to insure a more intimate mixture of the combustion air with the fuel.

In testimony of which invention, I have hereunto set my hand, at Philadelphia, on this 14th day of July, 1915.

LARS H. BERGMAN.. 

